When a side mirror for vehicles is mounted, an operator fixes the side mirror with screw tightening or the like after temporarily fixing the side mirror once on a door panel at a vehicle side. FIG. 6 is an illustration showing an example of a configuration of a conventional side mirror. In the configuration, the door panel has a vehicle hole having a circular shape. In addition, a mounting base of the side mirror has a boss covered with a gasket, and the gasket has a rib which is protruded to a side surface direction of the boss.
When the side mirror is mounted, the rib is lapped to the vehicle hole by inserting the boss of the mounting base into the vehicle hole of the door panel, thereby causing a frictional force, the side mirror is temporarily held (temporary fixing) by the force.
In addition, in a mounting structure of a side mirror, a structure where an engagement claw is formed at an edge of a standard boss having a cross-shaped section has been known in the past (patent literature 1). The engagement claw is formed to protrude to a backward of a side mirror base (mounting base), and a rear part is tapered toward an edge.
Patent literature 1: Japanese Laid-Open Patent Publication No. H7-223490